#[proc_macro_attribute] 只能在定义为过程宏的 crate 中使用,且该 crate 的 Cargo.toml 文件中必须指定 crate-type 为proc-macro。这是因为属性宏需要在编译时运行,并且它们的输出是 Rust 代码,因此它们必须被编译为一个特殊的 crate 类型,以便 Rust 编译器能够识别和处理它们。 指出用户问题中提到的错
问如何创建proc_macro_attribute？ENRust是一门现代的、安全的系统级编程语言，它提供了丰富的元编程特性...
ENimport "fmt" func main() { dict := map[string]int{"key1": 1, "key2": 2} ...
86 + #[proc_macro_attribute] 87 + pub fn py_class(attr: TokenStream, item: TokenStream) -> TokenStream { 88 + let attr = parse_macro_input!(attr as AttributeArgs); 89 + let item = parse_macro_input!(item as Item);
This is aproc_macrocrate to help keeping the code footprint of generic methods in check. Often, generics are used in libraries to improve ergonomics. However, this has a cost in compile time and binary size. Optimally, one creates a small shell function that does the generic conversions and...
例如，图 1 中报警的消息文本“设备 2故障，原因：电气故障”，这其中“电气故障”信息就是在分析报警...
ENpackage org.lgy.study.enumstudy; public enum Operation{ PLUS,MINUS,MULTI,DIVIDE;...
I was making a derive proc macro and stumbled upon this weird error, and was told on the rust discord that this might be a bug. Basically, I have a proc macro that uses a helper attribute like this: #[proc_macro_derive(Test, attributes(t...
Macro Code usedarling::{Error,FromMeta};usedarling::ast::NestedMeta;usesyn::ItemFn;useproc_macro::TokenStream;#[derive(Debug,FromMeta)]structMacroArgs{#[darling(default)]timeout_ms:Option<u16>,path:String,}#[proc_macro_attribute]pubfnyour_attr(args:TokenStream,input:TokenStream)->TokenStream{...
#[declare_sql_function]extern"SQL"{fncoalesce(x:sql_types::Nullable<sql_types::VarChar>,y:sql_types::VarChar,)-> sql_types::VarChar;} Rust-analyzer emits "unsafe" hints forextern {}function blocks even if these blocks are completely consumed by an proc-macro attribute and never generate ...